Fig. 2: Temporal activation of Mn oxidase gene promoters of P. putida GB-1 in surface-grown microcolonies and liquid-suspended cultures.
a, b Surface area of PmnxG (a) PmcoA (b) fluorescing cells (in blue or magenta) relative to the total microcolony surface area (in gray) at entry into stationary phase as indicated by the dotted lines, expressed as a percent (%). The growth curves, calculated as the increase in microcolony surface area over time, represent the average of 13 replicates for PmnxG and 21 replicates for PmcoA. Shaded areas represent the 95% confidence interval around the mean. Growth rates (µ) are calculated during the exponential phase, as indicated by the black line and its linear regression coefficient (R2). c, d Proportion of individual (open symbols) or aggregate cells (closed symbols) fluorescing over time (blue and magenta lines) in liquid-suspended cultures for c PmnxG and d PmcoA. The shaded areas represent the standard deviation around the mean and are connected for visualization purposes (n = 3). Relative OD corresponds to the culture turbidity (as OD600, in gray) normalized by the maximum OD600. Growth curves for liquid-suspended cultures were measured in 5 replicates using a plate reader. The decrease in relative OD after the exponential phase reflects cell aggregation. Separate relative OD600 measurements for cultures grown in flasks are shown by the gray symbols.
